Farmer flags environment angle in Northland floods

A 200mm deluge on March 18-20 inundated farmland, closed roads and delayed milk collections.

Hikurangi swamp land was among the worst hit, losing 3500ha to flooding. Ben Smith saw 60% of his farm go under and was still pumping a week later.

Collective pasture renewal costs are estimated at $49m, but Smith says the effects on the river and the Kaipara Harbour worry him most.

"It's an environmental time bomb... We've been liasing with the council and fencing off waterways but what's the point when something like this happens?" he said to Rural News.

Smith blames an outdated catchment and river management system for the situation and says changes are needed throughout the Wairua River and Kaipara Harbour catchment.

Whangarei District Council waste and drainage manager Andrew Carvell says the Hikurangi flood control system was designed in the 1960s to handle a one-in-five-year storm, but recent large storms have prompted suggestions the design is out-of-date.

The council has raised the future of the scheme with farmers and other stakeholders and council's immediate aim is to repair damaged stop banks and adjust spillways.

"Our main goal is to get the flood control system working to its intended capacity," says Carvell.

Resource consents allow 40,000L/sec. to be pumped into the Wairua River. Carvell says the council and farmers are further limited because they can't pump when the river is already full.

The council is working with a Kaipara Harbour water quality focus group to find a whole-system solution but the number of people and organisations involved make it difficult.

"Kaipara Harbour encompasses two regional councils and three district councils... Things can get very complicated."